1 files changed, 67 insertions, 63 deletions

diff --git a/src/ldpc_noise.c b/src/ldpc_noise.c
index c641dac..a4c398c 100644
--- a/src/ldpc_noise.c
+++ b/src/ldpc_noise.c
@@ -1,4 +1,4 @@
-/* 
+/*
   FILE...: ldpc_enc.c
   AUTHOR.: Don Reid
   CREATED: Aug 2018
@@ -7,71 +7,75 @@
   of LDPC code with PSK modem.
 */
 
+#include <errno.h>
+#include <math.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <stdint.h>
 #include <string.h>
-#include <math.h>
-#include <errno.h>
 
 int main(int argc, char *argv[]) {
-    FILE        *fin, *fout;
-    float	datain, dataout;
-
-    if (argc < 3) {
-        fprintf(stderr, "\n");
-        fprintf(stderr, "usage: %s InputFile OutputFile NodB\n", argv[0]);
-        fprintf(stderr, "\n");
-        exit(1);
-    }
-
-    if (strcmp(argv[1], "-")  == 0) fin = stdin;
-    else if ( (fin = fopen(argv[1],"rb")) == NULL ) {
-        fprintf(stderr, "Error opening input bit file: %s: %s.\n",
-                argv[1], strerror(errno));
-        exit(1);
-    }
-        
-    if (strcmp(argv[2], "-") == 0) fout = stdout;
-    else if ( (fout = fopen(argv[2],"wb")) == NULL ) {
-        fprintf(stderr, "Error opening output bit file: %s: %s.\n",
-                argv[2], strerror(errno));
-        exit(1);
-    }
-
-    double NodB = atof(argv[3]);
-    double No = pow(10.0, NodB/10.0);
-    double sum_xx = 0; double sum_x = 0.0; long n = 0;
-    
-    fprintf(stderr, "Uncoded PSK Eb/No simulation:\n");
-    fprintf(stderr, "No    = % 4.2f dB (%4.2f linear)\n", NodB, No);
-    fprintf(stderr, "Eb    = % 4.2f dB (%4.2f linear)\n", 0.0, 1.0);
-    fprintf(stderr, "Eb/No = %4.2f dB (%4.2f linear)\n", -NodB, pow(10,-NodB/10.0));
-    
-    while (fread(&datain, sizeof(float), 1, fin) == 1) {
-
-	// Gaussian from uniform:
-	double x = (double)rand() / RAND_MAX;
-        double y = (double)rand() / RAND_MAX;
-        double z = sqrt(-2 * log(x)) * cos(2 * M_PI * y);
-
-	double noise = sqrt(No/2) * z;
-	dataout = datain + noise;
-
-        fwrite(&dataout, sizeof(float), 1, fout);        
-
-        // keep running stats to calculate actual noise variance (power)
-        
-        sum_xx += noise*noise;
-        sum_x  += noise;
-        n++;
-    }
-
-    fclose(fin);  
-    fclose(fout); 
-
-    double noise_var = (n * sum_xx - sum_x * sum_x) / (n * (n - 1));
-    fprintf(stderr, "measured double sided (real) noise power: %f\n", noise_var);
- 
-    return 0;
+  FILE *fin, *fout;
+  float datain, dataout;
+
+  if (argc < 3) {
+    fprintf(stderr, "\n");
+    fprintf(stderr, "usage: %s InputFile OutputFile NodB\n", argv[0]);
+    fprintf(stderr, "\n");
+    exit(1);
+  }
+
+  if (strcmp(argv[1], "-") == 0)
+    fin = stdin;
+  else if ((fin = fopen(argv[1], "rb")) == NULL) {
+    fprintf(stderr, "Error opening input bit file: %s: %s.\n", argv[1],
+            strerror(errno));
+    exit(1);
+  }
+
+  if (strcmp(argv[2], "-") == 0)
+    fout = stdout;
+  else if ((fout = fopen(argv[2], "wb")) == NULL) {
+    fprintf(stderr, "Error opening output bit file: %s: %s.\n", argv[2],
+            strerror(errno));
+    exit(1);
+  }
+
+  double NodB = atof(argv[3]);
+  double No = pow(10.0, NodB / 10.0);
+  double sum_xx = 0;
+  double sum_x = 0.0;
+  long n = 0;
+
+  fprintf(stderr, "Uncoded PSK Eb/No simulation:\n");
+  fprintf(stderr, "No    = % 4.2f dB (%4.2f linear)\n", NodB, No);
+  fprintf(stderr, "Eb    = % 4.2f dB (%4.2f linear)\n", 0.0, 1.0);
+  fprintf(stderr, "Eb/No = %4.2f dB (%4.2f linear)\n", -NodB,
+          pow(10, -NodB / 10.0));
+
+  while (fread(&datain, sizeof(float), 1, fin) == 1) {
+    // Gaussian from uniform:
+    double x = (double)rand() / RAND_MAX;
+    double y = (double)rand() / RAND_MAX;
+    double z = sqrt(-2 * log(x)) * cos(2 * M_PI * y);
+
+    double noise = sqrt(No / 2) * z;
+    dataout = datain + noise;
+
+    fwrite(&dataout, sizeof(float), 1, fout);
+
+    // keep running stats to calculate actual noise variance (power)
+
+    sum_xx += noise * noise;
+    sum_x += noise;
+    n++;
+  }
+
+  fclose(fin);
+  fclose(fout);
+
+  double noise_var = (n * sum_xx - sum_x * sum_x) / (n * (n - 1));
+  fprintf(stderr, "measured double sided (real) noise power: %f\n", noise_var);
+
+  return 0;
 }